We hypothesize that the dietary requirement for the branched chain amino acids (BCAA) in an older strength-trained (ST) population will be greater than the current recommendation (RDA). If so, a greater intake of BCAA together with ST is necessary if one aims to maximize muscle protein synthesis (MPS). Currently, the BCAA requirement in the ST older population (55-65 y) is unknown. This is critical information especially given the value of ST for overall health.